The objectives of this contract are to provide statistical and computational expertise and resources to summarize, analyze, and aid in the interpretation of data from various laboratory animal experiments conducted by the National Institute of Environmental health Sciences (NIEHS). These investigations consist of subchronic studies, carcinogenesis experiments, and other toxicological studies. Evaluation of NIEHS subchronic studies consists of providing statistical analyses of survival, organ and body weights, clinical chemistry, hematology, and pathology observations, variables which are used in the selection of doses for long-term carcinogenicity experiments. The contractor also provides support to the NIEHS Reproductive Assessment by Continuous Breeding Project and other special studies. For NIEHS long=term studies, the contractor has responsibility for developing and maintaining statistical software for the Toxicology Data Management System (TDMS). This includes developing and maintaining programs for the analysis of tumor incidence and survival and providing summary statistics for food and water consumption and weight gain. The contractor is also responsible for maintaining a database on historical control tumor incidence.